Switch structure



June 14, 1932. A, PENN 1,862,631

swITcH STRUCTURE Filed July 1e, 1928 @Wwf Patented June 14 1932 UNITEDSTATES PATENTOFFICE ALBERT PENN, 0I' DES MOINES, IOWA, ASSIGNQB TO PENNELECTRIC SWITCH DEB MOINES, ICWA, A. CORPORATION 0F IOWA O0., OF

SWITCH BTBUGI'UBE Application led AJ'uly 13, 1928. Serial N0. 293,270.

The object of m invention is to provide a switch structure o simple,durable and comparatively inexpensive construction: v

A further ob]ect of my invention 1s to provide a switch structure inwhich a pair of contact members are adapted to be separated from eachother in a magnetic field whereby the arc formed between the contactmembers is blown out and thereby quickly extlnguished.

Still a further object is to provide means in such a structure toprevent the are from jumping to the magnet which causes the magneticfield and thereby quickly extinguishing the arc which would otherwise beprolonged as when the arc jumps to the magnet.

A further object is to provide a switch structure so constructed thatthe capacity of the switch will not be affected by reversal of the wireswhen connected to the terminals of the switch whereby the switch is moreeasily connected in an electric circuit without the bother ofdetermining the polarity of the wires and all chance of connecting theswitch wrong is thereby eliminated.

More particularly, it is my object to provide a switch structure of theabove referred to character in which it is immaterial whether thenegative or the positive wire of an electric circuit is connected witheither terminal of the switch. Incidentally, the capacity of a switch ofthe character herein disclosed, is greater when the current flows in onedirection through the switch than when it flows in another directiontherethrough, providing the permanent magnet is electrically connectedwith one of the terminals of the switch. It has therefore, been myobject to insulate the permanent magnet from such terminall of theswitch with the result that the electric wires of the circuit in whichthe switch is interposed, may be connected with the terminals of theswitch regardless of the polarity of the wires whereby the capacity ofthe switch is at maximum regardless of how the wires are connected.

With these and other objects in view my invention consists in theconstruction, arrangement and combination of the'various parts of mydevice, whereby the objects contemplated are attained, as hereinaftermore fully set forth, pointed out in my claims and illustrated in theaccompanying drawing. Although the invention is susceptible of a varietyof embodiments, it is unnecessary to fully describe and illustrated morethan one in order to give Va full understanding of the invention bothfrom its structural and functional stand oints. Accordingly, I haveillustrated a re erred and desirable embodiment of the invention in theaccompanying drawing, in which:

Figure 1 is a side elevation of my switch structure showing it mountedwithin a casing, the casing being shown in section.

Figure 2 is a sectional view on the line 2-2 of Figure 1.

Figure 3 is a sectional view on the line 3*-3 of Figure 1.

Figure 4 is an enlarged side elevation of a portion of the switchstructure showing the circuit being broken and Figure 5 is adiagrammatic view illustrating an arc jumping from a contact to one ofthe poles of the magnet.

On the accompanying drawing, I have illustrated one embodiment of myinvention wherein my construction for reducing the duration of the arcand thereby increasing the capacity of the switch is shown. The switchstructure consists of a base 10 having upstanding brackets 12 securedthereto. A supporting member 14 is mounted on the brackets 12 and isformed preferable of insulating material.

A stationary contact 16 is mounted on a Contact bracket 18 on thesupporting bar 14. The bracket 18 is held in position with respect tothe supporting bar-14 by a screw 20. A nut 22 on the screw 20 serves toallow for the connection of an electric conductor to the screw 20 andthus to the contact 16.

A permanent magnet 24 of the horseshoe type is mountedon the bar 14 andheld thereaga-inst by the bracket 18. A sheet of insulating material 26is positioned between the bracket 18 and the magnet 24 and an insulatingbushing 28 surrounds the screw 20 where it extends between the poles ofa magnet 24 as clearly shown in Figures 2 and 3 of the drawing. Thepurpose of the insulating plate 26 and the insulating bushing 28 is veryimportant and will hereinafter be more fully referred to. The poles arenecessarily arranged close together so as to intensify the magneticfield as much as possible.

ltovable contacts 30 are mounted on a spring arm 32. The spring arm 32is connected `with an armature arm 34 which is pivotally mounted on thebar 14. A bracket 36 and pivot pin 38 serve to provide for such pivotalmovement. The contacts 30 pass through openings formed in the arm 34.

A stationary adjustable contact 40 is mounted on the bar 14 andelectrically connected by a metallic bracket 42 to the screw 20. Acontact 42 is secured to the armature arm 34. The armature arm 34 iselectrically connected by a iexible cable 44 to a terminal screw 46 towhich another wire of the electric circuit in which the switch isincluded, may be connected by means of a nut 48.

The bracket 42 is provided with an extension 50 adapted to serve as astop for the armature arm 34. The undersurface of the extension 50 isfaced with insulation 52 which is adapted to be struck by a spring shockabsorber arm 54 secured to the armature arm 34.

The armature arm 34 is actuated by means of a lever 56 connected theretoby a resilient connection 58. An automatic or hand control device of anykind may be connected with the lever 56 which is pivotally mounted at60. In Figure l of the drawing, I have illustrated a rod 62 which may beconnected with a pressure actuated diaphragm, a float or other type ofcontrolling device.

Movement of the rod 62 in the direction of' the arrow 64. will causeexpansion of the spring 58 until such time as the force of the springwill overcome the magnetism of the magnet 24 which tends to hold thearmature arm 34 with the contacts 4() and 42 together.

In this position, the contacts 16 and 30 are held together by the springarm 32 which is sprung slightly away from the armature arm Upon thespring 58 being stretched far enough to move the armature arm 34 in thedirection of the arrow 66, the armature arm will immediately be in aweaker magnetic field and the force of the extended spring 58 will causeit to continue to move in the direction ofthe arrow 66 whereby thecontacts are opened quickly. The contacts 40 and 42 will open first andthese contacts I call the main contacts since they are largest and carrymost of the current.

Immediately after the main contacts have been separated, the spring arm32 will be engaged by the armature arm 34 and the contacts 16 and 30will be broken in the magnetic field of the magnet 24. As illustrated inFigure 4, the main contacts 40 and 42 have already been separated andthe secondary contacts 16 and 30 have just been separated. Theirseparation causesy the arc 68 which is blown sidewise as indicated, dueto the magnetic action of the magnet 24 on the arc. This action is anold principle which has long been recognized.

I have found that in usin my switch for controlling direct current, t atreversal of the wires to the binding osts 20 and 46, makes aconsiderable di erence in the capaci'ty of the switch. For instance,when the wires are connected one way the capacity of the switch is abouttive amperes while reversing the wires will increase the capacit of theswitch to about thirty amperes. I wi l attem t to describe the action ofthe switch where y this difference may be illustrated.

It is well known that the separation of contact points connected in anelectric circuit will produce an arc. In such an event the contactpoints 16 and 30 are roperlyr considered conducting electrodes.lectriclty is conducted through an arc by means of electrons. Electronsare set free from the conducting electrodes by the action of hightemperature. In forming an arc by separating electrodes which arecarrying current, intense heat is produced at the point of separation,electrons are emitted, and conduction of current takes place across theair space between the electrodes by means of the electron stream. In thecase of an are discharge the electron carriers of electricity areemitted at the negative electrode known as the cathode and extend to thepositive electrode known as the anode.

Taking for example,'the switch structure herein disclosed, with theexception of omitting the insulating plate 26 and the insulatingbushing, the cathode will be the movable or the stationary contactdepending upon the polarity of connection in the circuit.

If the switch is connected so that the sta.- tionary contact 16 is thenegative or cathode, the arc stream will be blown by the magnetic fieldof the permanent magnet 24 making the current path through the air gaplonger and longer until finally the arc is ruptured. If so, theoperation of the switch is satisfactory. The arc stream in being blownaside, however, will touch the face of the permanent magnet asillustrated in Figure 5, since the magnet is close to and electricallyconnected with the cathode 16.

On account of the fact that the permanent magnet is cold and hasrelatively high heat receiving capacity, current will not continue toflow between the movable contact and the permanent magnet because of thefact that now the permanent magnet is the cathode and being relativelylarge, it is not heated to a ktemperature which will give off electrons.Therefore, even though the arc stream should suiciently hightemperature.

touch the permanent magnet, the arc will be ru tured.

aking as a further example, the hypothetical switch referred to in theprecedmg three paragraphs and assuming the movable contact as thenegative or cathode, on opening the switch for breaking the circuit, anarc stream will result and the arc will be blown aside by the magneticinfluence of the permanent magnet 24 until it touches the face of themagnet whereupon the magnet will act as the anode and current willcontinue to flow because we now have a hot cathode, electrons are beingemitted and they carry the current across the arc gap to the anode(permanent magnet).

In order for the arc stream to continue, as long as possible during thespreading of the contacts, it is immaterial whether the anode is hot orcold. Therefore, the fact that the permanent magnet is relatively coldmakes no difference when the movable contact is the cathode.

In my improved type of switch as described, wherein the permanent magnet24 is insulated from the stationary contact 16,

the current cannot flow through the permanent magnet. Therefore,interruption of the current is successfully accomplished.

It is, therefore, evident that the behavior of my improved switch isexactly what would be expected from a consideration of the fundamentalprinciples of the action of an electric arc. It has long been known thatan arc can be sustained only when the cathode is at may be either hot orcold andv I vhave taken advantage of these principles in my device.

It, therefore, becomes obvious that the insulations 26 and 28 wherebythepermanent either of the sides of the electric circuit, is

The anode magnet 24 is not electrically7 connected with taining saidmagnet against said base, a stationary contact on said plate between thepoles of said magnet and a movable contact engageable therewith.

v 3. In a switch struc-ture, a base, a horseshoe magnet having one sidethereof flatwise thereagainst, a plate againstthe opposite side of saidmagnet, means for retaining said plate against said magnet and therebyretaining said magnet against said base, an-

extension on said plate located between the poles of said magnet, astationary contact on said extension and a movable contact engageabletherewith.

Des Moines, Iowa,` June 29, 1928.

ALBERT PENN.

very necessary if a fool proof switch is to be.

made. By fool proof I mean a switch in which it is immaterial whetherthe negative or positive wire is connected with the screw v20. As longas the magnet is insulated from either side of the electric circuit, itcannot act either as an anode or a cathode and it is therefore,immaterial which way the wires are connected to the switch.

A great many changes in the structural details can be made in the switchstructure which Il have herein described and yet the real spirit andpurpose of the invention will not be departed from. It is therefore myintention to cover by my claims, any modied forms of structure or use ofmechanical equivalents, which may be reasonably ineluded within theirscope.

I claim as m invention:

1. In a switc structure, a base, a` magnet i thereagainst, a plate forretaining lthe magnet in such posltion thereagainst, an extension on theplate between the poles of the lll

